From 7ca3c40b50b385ead6b8bc4c54de97b61d11a12a Mon Sep 17 00:00:00 2001 From: Roberto Ierusalimschy Date: Fri, 10 Jan 2025 13:54:51 -0300 Subject: Another way to compile goto's The compilation of a goto or a label just create an entry and generate boilerplate code for the gotos. As we don't know yet whether it needs a CLOSE, we code a jump followed by a CLOSE, which is then dead code. When a block ends (and then we know for sure whether there are variables that need to be closed), we check the goto's against the labels of that block. When closing a goto against a label, if it needs a CLOSE, the compiler swaps the order of the jump and the CLOSE, making the CLOSE active. --- testes/code.lua | 13 +++++++++++-- 1 file changed, 11 insertions(+), 2 deletions(-) (limited to 'testes/code.lua') diff --git a/testes/code.lua b/testes/code.lua index 08b3e23f..50ce7392 100644 --- a/testes/code.lua +++ b/testes/code.lua @@ -412,13 +412,22 @@ checkequal(function (l) local a; return 0 <= a and a <= l end, function (l) local a; return not (not(a >= 0) or not(a <= l)) end) --- if-break optimizations check(function (a, b) while a do if b then break else a = a + 1 end end end, -'TEST', 'JMP', 'TEST', 'JMP', 'ADDI', 'MMBINI', 'JMP', 'RETURN0') +'TEST', 'JMP', 'TEST', 'JMP', 'JMP', 'CLOSE', 'JMP', 'ADDI', 'MMBINI', 'JMP', 'RETURN0') + +check(function () + do + goto exit -- don't need to close + local x = nil + goto exit -- must close + end + ::exit:: + end, 'JMP', 'CLOSE', 'LOADNIL', 'TBC', + 'CLOSE', 'JMP', 'CLOSE', 'RETURN') checkequal(function () return 6 or true or nil end, function () return k6 or kTrue or kNil end) -- cgit v1.2.3-55-g6feb